Sewing machine



March 2 1926. 1,575,112

-:' A. B. FOWLER SEWING MACHINE Original Filed Oct. 21, 1920 2Sheets-Sheet 1 March 2 1926. 1,575,112

A. E3. FQVVLER SEWING MACHINE Original Filed Oct. 23., 1920 2SheetsSheet 2 Patented Mar. 2, 1926.

UNITED STATES PATENT OFFICE.

ALFRED B. FOWLER, OF BEVERLY, MASSACHUSETTS, ASSIGNOR TO UNITED SHOEMACHINERY CORPORATION, OF IPATERSON, NEW JERSEY, A CORPORATION OF NEWJERSEY.

SEWING MACHINE.

Application filed October 21, 1920, Serial No. 418,451. Renewed March 5,1925.

To all whom it may concern:

Be it known that I, ALFRED B. FOWLER, a citizen of the United States,residing at Beverly, in the county of Essex and State of Massachusetts,have invented certain new and useful Improvements in Sewing Machines;and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

The present invention relates to sewing machines and more particularlyto wax thread chain stitch inseam shoe sewing machines, although certainfeatures of the invention are applicable to other types of sewingmachines.

In applicants co-pending application filed of even date herewith, SerialNo. 418,450 a wax thread chain stitch inseam shoe sewing machine isillustrated and described which is provided with a main take-up fordrawing thread from the supply and for exerting strain on the threadwhile the needle is in its forward position, and for giving up threadduring the thread measuring move ment of the thread arm, the loopingmovement of the looper and the first part of the retracting movement ofthe needle. The machine is also provided with a spring pressed.auxiliary takeup for exerting a strain on the thread during the latterpart of the re tracting movement of the needle. In the operation ofsewing machines, particularly of this type, it has been found that thestrain which must be exerted on the thread to produce the best resultsvaries with the speed at which the machine is operated, a greater strainordinarily being required to produce a tight seam when the machine isoperated at a low speed than when the machine is operated at a highspeed. To secure this resultin the machine of said co-pendingapplication, means is provided for varying the tension. of the auxiliarytake-up spring, the tension of the spring beingincrcased upon areduction in the speed of the machine and being decreased upon anincrease in the speed of the machine.

An object of the presentinvention is to provide novel and improved;means in a sewing machine for regulating the strain cut that the effectof thus varying the duration of the strain is to increase the amount ofeffectiveness of the strain. The preferred embodiment of the inventionis provided with a high speed driving mechanism, a low speed drivingmechanism, and means for adjusting said stitch setting mechanism uponshifting from the high to the low speed driving mechanism to increasethe duration of the strain upon the thread, and upon shifting back tothe high speed driving mechanism to decrease the duration of the strain,the variation in the duration of the strain being such as to result inthe desired tightness of seam being secured at both speeds. The presentembodiment of the invention is provided with a main take-up for exertinga strain on the thread and for drawing thread from the supply when theneedle is in its advanced position, and for providing slack or freethread for the stitch forming devices, and is further provided with aspring pressed auxiliary take-up that tends to be urged in one directionto exert a strain on the thread during the retracting movement of theneedle. The auxiliary takeup is provided with a stop'for limiting themovement thereof in said direction, and with means acting upon areduction in the speed of the machine to raise the stop to allow agreater movement of the auxiliary take-up in said direction during theretract ing movement of the main take-up. It will be apparent that theeffect of thus raising the stop at this time is to lengthen the path oftravel of the thread and, hence, to decrease the amount of slack or freethread provided by the main take-up for the stitch forming devices, sothat during the retracting movement of the needle the needle willcooperate sooner with the auxiliary take-up to exert a strain on thethread. Preferably,

scribed and claimed, the advantages of which will be obvious to thoseskilled in the art.

The several features of the invention will be clearly understood fromthe following description and accompanying drawings, in

' which Figure l is a front elevation of the head of a wax thread chainstitch inseam shoe sewing machine embodying the features in theirpreferred form; Fig. 2 is a side elevation on an enlarged scale of aportion of the head of the machine with a side of the casing removed;and Fig. 3 is a detailed sectional view taken on the line 33 of Fig. 2

of a portion of the mechanism for control ling the strain exerted on thethread.

The sewing machine illustrated in the drawings is provided with a curvedhook needle 2, a needle carrier i, a looper 6, a thread arm 8, a backgage 10, a back rest or hunter 12, and a thread tcnsioning devicecomprising a tension wheel 1%. The machine is also provided with a highspeed driving mechanism comprising a pulley 16 mounted on the drivingshaft 18 of the machine and a low speed driving mechanism comprising aworm wheel 20 mounted on the driving shaft. The high speed drivingmechanism is thrown in upon the depression of a rod 22 connected with atreadle mechanism at the base of the machine, and is thrown out and thelow speed driving mechanism is thrown in upon the rod being released.The rod 22 is connected with the driving mechanisms through an arm 24;secured to one end of a rock shaft 26 that carries a forked arm 28engaging a clutch sleeve 30 mounted to slide on and rotate with thedriving shaft 18. When the treadle rod 22 is released to throw out thehigh speed driving mechanism and to throw in the low speed drivingmechanism, the upward niovement of the arm 2% which is effected by meansof a torsion spring 31 connected with the arm, is limited by theengagement of a stop lug 32 thereon with the lower end of a latch lever34 pivoted on the frame of the machine. Ata predetermined point in therotation of the driving shaft after the low speed driving mechanism isthus thrown in, the latch lever 34 is released from the stop lug 32 by acam carried by the driving shaft allowing the arm 24 to be furthercarried upwardly by its spring which shifts the clutch sleeve 30 intoposition so that upon the completion of a predetermined number ofdegrees of rota tion of the driving shaft after the latch lever 3% isreleased, the low speed driving mechanism is thrown out, and stoppingdevices act to stop the shaft in a predetermined angular position. insewing about the toe of a pointed toe shoe, it is desirable that themachine shall be run at a uniformly low speed, and it will be apparentthat this may be accomplished in the illustrated machine by the operatorreleasing the treadle rod 22 only suliiciently to throw in the low speeddriving mechanism without rendering the stopping devices of the machineactive, and that upon again depressing the trcadle rod 22 the drivingmechanism may be shifted back to high speed. The parts above describedmay be and preferably are the same as the corresponding parts of themachine illustrated and described in applicants copending applicationSerial No. 298,589, filed May 21, 1919, to which reference may be hadfor a full and complete description of the same.

The main take-up comprises a thread truck 36 mounted on the free end ofan arm 38 projecting from a sleeve 40 which is loosely mounted on a studshaft 12 secured to the frame of the machine. The main takeup isactuated by an arm projecting upwardly from the sleeve d0 and having itsfree end pivotally connected with a cam actuated link 4-6. The auxiliarytake-up which is interposed between the main takeup and the tensionwheel lei comprises a thread truck 48 mounted on the free end of an arm50 projecting from a sleeve which is loosely mounted on the sleeve 40 ofthe main take-up. The auxiliary take-up arm 50 is urged upwardly by acoiled spring 5% connected therewith until a projection thereon abutsagainst the lower end of an abutment 56. The thread passes from thetension wheel over the thread truck 48, beneath a thread truck 58loosely mounted on the auxiliary takeup sleeve 52, over the thread truck36 of the main take-up, and thence through the looper to the work.

The thread handling devices of the ma chine illustrated in the drawingsare so arranged and operated that the main take-up acts to exert astrain on the seam and to draw oti thread for the next loop from thetension wheel when the needle is in its forward position and extendedthrough the work. The main take-up then falls during the bread measuringmovement of the thread arm, during the looping movement of the looper,and during the first part of the retracting movement of the needle.During the latter part of the retracting movement of the needle, itexerts a pull on the thread to tighten the preceding loop, such pullmoving the auxiliary take-up arm 50 away from the abutment 56 againstthe tension of the auxiliary take-up spring 5%.

To render the action of the main take-up,

.the auxiliary take-up and the needle reliable and uniform under allconditions of sewing, means are provided which insure that the pullexerted upon the thread by the needle during the latter part of its retracting movement shall always be against the resistance offered by theauxiliary tension spring 54 and not against the resistance offered bythe tension wheel 14:. To secure this result the needle carrier 4 isprovided with a cam surface 60 to cooperate with the end of an arm 62projecting from the auxiliary take-up sleeve 52. The cam surface- 60acts to positively raise the auxiliary takeup and to hold the auxiliarytake-up in raised position during the action of the main take-up insetting the stitch, so that during the latter portion of the taking upaction of the main take-up the auxiliary take-up is practically lockedin a position in which the arm 50 of the auxiliary takeup is nearly incontact with the abutment 56. As the main take-up moves to give upthread, however, the retracting movement of the needle carrier moves thecam surface 60 away from the path of the end of the .arm 62 leaving theauxiliary take-up free to be moved against the tension of the spring 54so that whenthe needle exerts a pull on the thread during the latterpart of its retracting movement the auxiliary take-up can yield to therequired extent without bringing up against a positive stop so as tocause any strain to be exerted on the thread in addition to that causedby the spring 54 of the auxiliary take-up. The parts of the main take-upand the auxilary take-up above described are of the same'constructionand mode of operation, except as hereinafter described, as thecorresponding parts of the machine illustrated and described in theco-pending application filed of even date herewith, hereinbeforereferred to.

In themachine illustrated in the drawings during the retracting movementof the main take-up, the auxiliary take-up arm 50 is raised by thespring 54 against the abutment 56 and the abutment is so positioned thata certain amount of slack or free thread is provided during the threadmeasuring movement of the thread arm, the looping movement of the looperand the first part of the retracting movement of the needle or until theneedle has retracted sufficiently to cooperate with the auxiliary takeupspring to exert a strain on the thread. It will be apparent that byraising the abutment 56 the path of travel of the thread may beincreased and, consequently, the amount of slack or free thread providedas above described for the stitch forming devices may be decreased. Theeffect of thus decreasing the slack or free thread obviously is toincrease the amount oreffectiveness of the strain on the thread as theneedle and take-up will act sooner to tension the thread during theretracting movement of the needle, and hence the duration of the strainat this time will be increased. As the machine illustrated in thedrawings is provided with a low speed driving mechanism for drivingthemachine at low speed, means is provided for raising the abutment 56upon shifting from the high to the low speed driving mechanism to suchposition that the amount or effectiveness of the strain exerted on thethread may be increased such a degree as to compensate for the reductionin the speed of the machine, resulting in the desired uniform tightnessof stitch being obtained at both speeds. To this end the abutment 56comprises a rod which is screw threaded through an aperture in a crossbar 64, the rod being adapted to be adjusted in the aperture and lockedin adjusted position by a lock nut 66. The cross bar is mounted to slideon a pin 68 secured to the frame of the machine, and is urged upward-'ly against nuts '70 threaded onthe upper end of'the bar by means of aspring 72 coiled about the pin and interposed between the bar and theframe. The cross bar 64; is connected by a cord 74: with a lugTG securedto the arm 24,- the cord 74 being connected to the lug by a block 78secured on the end of the cord extending through an aperture in theupper end of the lug 76, and provided with a head 79 at its lower end.lVith this construction it will be ap parent from an inspection of thedrawings that upon depressing the treadle rod 22 to throw in the highspeed driving mechanism the lug 76 on the arm 2- will act through thehead of the block 78, cord 7 and cross bar 64 to lower the abutment rod56, and that upon releasing the treadle rod 22 sufficiently to throw inthe low speed driving mechanism without rendering the stopping devicesactive, the cord 74 will be released to permit the spring to move theabutment rod to its raised position, which position is such that therequisite increase in the strain exerted on the thread is obtained inaccordance with the reduction in the speed of the machine.

In the illustrated machine the outer end ofthe spring 54 is secured to ascrew 30 which is adapted to be adjusted and locked in adjusted positionby means of lock nuts 82.

lVhile it is preferred to employ the specific construction andarrangement of parts illustrated and described, it is to be under--stood that this construction and arrangement is, not essential except sofar as specilied in the claims, and may be changed or modified withoutdeparting from the broader features of the invention.

The nature and scope of the presentinvention having been indicated andamachine embodying the .several teatures of the tion, high and low speeddriving mechanisms,-mechanism for exerting a strain on the thread, andmeans forshitting from the high to the low speed driving mechanism andfor simultaneously adjusting said mechanism for exerting a strain' onthe thread to increase the duration of said strain.

3. A sewing machine having, in combination, stitch forming devices, atake-up, a spring for urging the take-up in one direction to exert astrain on the thread, and means acting upon a variation in the speed ofthe machine for adjusting the take-up to vary the duration of the strainwhile the tension of said spring remains constant.

i. A sewing machine having, in combination, stitch forming devices,mechanism for exerting a strain on the thread, and means acting upon avariation inthe speed of the machine for adjusting said mechanism toVary the duration of the strain.

5. A sewing machine'having, in comhination,-stitch forming devices, atake-up tending tomove in one direction to exert a strain on the thread,-a stop for limiting the movement of the take-up in such direction, andmeans for adjustingthe position of the stop to vary the amount of saidstrain upon a change in the speed ofthe machine.

6. A sewing machine having, in combination, stitch forming devices, atake-up, a

spring for urging the take-up in one direction to exert a strain on thethread, a stop for limiting-the movement ofthe take-up in suchdirection, and means for adjusting the stop to increase the amount ofsaid strain upon a reduction in the speed of the machine.

7. A. sewing machine having, in combination, stitch forming devicespatake-up tend ing to move in one direction to exert a strain on thethread, astop for limiting the movement of the take-up in suchdirection, and means for adjusting the stop to increase saidstrain upona reduction in the speed of the machine, and for adjusting the stop todecrease said strain on the thread upon an increase in the speed of themachine.

8. A sewing machine having, in combination, stitch forming devicesincluding a needle, a main take-up mechanism for exertmg a strain on thethread while the needle is inits forward position, an auxiliarytakeupmechanism for exerting a strain on the thread during the retractingmovement of the needle, and means for adjustingsaid auxiliary take-upmechanism to increase the path of travel of the thread to increase thestrain thereby exerted on the thread upon a reduction-in the speed ofthe machine.

9. A sewingmachine having, in comhination, stitch forming devicesincluding a needle, a take-up mechanism for exerting a strain on thethread during the retracting movement of the needle, and means actingupon a change in the speed of the machine for adjusting the take-upmechanism to increase the duration of said strain.

lOaA sewing machine having, in combination, stitch forming devices, .atake-up mechanism for exerting a strain on the thread, .and means actingupon. a reduction in the speed of the machine to adjust the take-upmechanism to lengthen the path of travel of the thread, and acting uponan increase in the speed of the machine to adjust said mechanism toshorten the path of travel of the thread.

11. A sewing machine having, in combination, stitch forming devices,mechanism for exerting a strain on the thread, and means acting upon avariation in the speed of the machine to adjust said -mechanism to varythe amount of said strain .while the intensitythereof remains constant.

12. A sewing machine having, in combination, stitch forming devices,mechanism for exerting a strain on the thread, and means actinguponarcduction in the speed of the machine for deflecting the thread fromitsnormal path of travel to increase the amount of said strain.

13. A sewing machine having, in combination, stitch forming devices,mechanism for exerting a strain on the thread, and

vmeans acting upon a variation in the speed of the machine to adjustsaid mechanism to vary the path of travel or" the thread.

14. A sewing n'i.acliine having, in combination, high and low speeddriving mechanisms, means for shifting from the high to the low speeddriving mechanism, stitch forming devices, mechanism for exerting astrain on the thread, and means acting upon bina-tion, stitch formingdevices including a needle, a main take-up mechanism for exerting astrain on the thread While the needle is in its advanced position, anauxiliary take-up mechanism for exerting a strain on the thread duringthe re'tractingmovement of the needle, and means acting upon a variationin the speed of the machine for adjusting said auxiliary take-upmechanism to vary the duration of the strain exerted thereby.

17. A sewing machine having, in combination, stitch forming devicesincluding a needle, a take-up mechanism for exerting a strain on thethread, and means acting upon a reduction in the speed of the machine toadjust the take-up mechanism to increase the duration of the strain andacting upon an increase in the speed of the machine to adjust thetake-up mechanism to decrease the duration of the strain.

18. A sewing machine having, in combination, stitch forming devices, atake-up mechanism for exerting a strain on the thread and for providingslack or free thread for the stitch forming devices, and means actingupon a variation in the speed of the machine for adjusting the take-upmechanism to vary the amount of slack or free thread provided for thestitch forming devices.

ALFRED B; FO'VVLER.

